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Measuring & Mapping

Where, how far, and how much? People have invented an astonishing array of devices to answer seemingly simple questions like these. Measuring and mapping objects in the Museum's collections include the instruments of the famous—Thomas Jefferson's thermometer and a pocket compass used by Meriwether Lewis and William Clark on their expedition across the American West. A timing device was part of the pioneering motion studies of Eadweard Muybridge in the late 1800s. Time measurement is represented in clocks from simple sundials to precise chronometers for mapping, surveying, and finding longitude. Everyday objects tell part of the story, too, from tape measures and electrical meters to more than 300 scales to measure food and drink. Maps of many kinds fill out the collections, from railroad surveys to star charts.

This is marked "W. & L. E. Gurley, Troy, N.Y." Gurley described it as a Surveyor's Transit with two verniers to the horizontal limb. The horizontal and vertical circles are silvered, graduated every 30 minutes of arc, and read by verniers to single minutes. A clamp and tangent to the telescope axis are present, as well as a gradienter attachment for determining gradients, distances, and differences of level. A variation scale on the face of the compass extends 35 degrees either way; the vernier reads to single minutes. The telescope has a fitting for a solar attachment. It was made after 1886, when Gurley introduced the bent standards, and before the introduction of serial numbers in 1908.

This simple mercury-in-glass thermometer has a brass scale housed in a maple case suitable for hanging on the wall. The scale is graduated in degrees from -40 to +150. and is marked "C.J. Tagliabue Mfg. Co. Bklyn. N.Y. Made in U.S.A."

This compass bears the inscriptions of two makers, "JAMES MORTON LIMITED SUNDERLAND" and "KELVIN, BOTTOMLEY & BAIRD LTD REGISTERED 16-20 CAMBRIDGE STREET, GLASGOW, PATENT No 22032 02." The Morton signature appears on the card. The Kelvin, Bottomley & Baird, Ltd. signature, which appears on the heavy brass bowl, refers to a firm that was in business, as such, from 1914 to 1965.

This is an aluminum compass with brass sights. The raised rim and beveled outer ring are graduated every degree, numbered every 10 degrees in quadrants from north and south, and adjustable for variation. The western half of the face is graduated to degrees, and equipped with a pendulum clinometer pivoted at the center. There is a circular level vial at NE. The four beveled edges of the plate are graduated, one to inches and tenths, one to inches and eighths, and two as protractors. The back of the plate has a diagram showing the arrangement of township numbering. The inscriptions read "KEUFFEL & ESSER CO NEW YORK" and "U.S. INDIAN FOREST SERVICE" and "32712." Keuffel & Esser noted that they had made many instruments of this sort for the United States Forest Service. The serial number indicates a date of around 1916.

This is an usually large compass, with an unusual skeletal design. The rim is graduated to 30 minutes. The variation arc on the north arm extends 20 degrees either way, and is read by folded vernier to single minutes. Two level vials are on the south arm. The "Thos Wall Cleveland O." signature refers to Thomas Wall (1797-1854), an instrument maker who worked in Cleveland, Ohio, in the years 1845-1854.

This level is marked, "A. S. Aloe Maker St. Louis No. 69 Blunt & Co. N. Y.” and it is difficult to know what to make of the signature. A. S. Aloe did sell various optical and mathematical instruments, but there is no evidence that he could or did make them. Blunt & Co., which was in business under this name from 1869 to 1874, probably did make instruments of this sort.

This telescope has an achromatic objective, a four-element erecting eyepiece, and a five-section brass draw tube covered with leather. It was probably made after the 1890 Tariff Act that required that all objects imported into the U.S. be marked with their country of origin.

This is a replica of a calculating instrument designed by Galileo Galilei to make use of his observations of the movements of four moons of the planet Jupiter. Galileo (1564–1642) sought to demonstrate that the moon’s regular motions could be used to determine time and that this, along with the positions of stars, could be used to determine longitude. He applied to the Spanish crown for its longitude prize, but was unsuccessful because the device was not considered practical.

On this instrument, the larger of the two revolving discs represents Jupiter and the smaller one the Sun. The discs are connected and their movements show when the four moons, observed from the Earth, enter and leave the shadow of Jupiter. The instrument’s plate is engraved in Latin with tables to predict these eclipses and it can also indicate time (though less precisely) from the observed positions of the moons.

Galileo discovered the moons of Jupiter in 1610 with a telescope of his own invention, and he used it to study their motions. In designing the giovilabio, he found it necessary to correct his earlier observations for the effect of the Earth’s revolution around the Sun, which added to the growing evidence supporting the Copernican system of a Sun-centered universe. It also seemed to contradict the traditional (Aristotelian) cosmology, supported by the Catholic Church, which theorized a stationary Earth about which all heavenly bodies moved. Galileo’s support for the Copernican system ultimately led to his trial and conviction for heresy.

This compass is marked "B. Stancliffe - Philada Maker" and "Warranted." It has a variation arc on the north arm that extends 22 degrees to either side; the vernier is moved by rack and pinion and reads to 5 minutes. A spirit level is on the south arm. The signature refers to Benjamin Stancliffe (1782-1834) who was born in England, apprenticed with his uncle, John Stancliffe, a noted instrument maker in London, and worked for Edward Troughton making sophisticated geodetic instruments for the fledgling United States Coast Survey. Stancliffe then migrated to America, appearing in Philadelphia directories as early as 1817. In 1828 he went into partnership with his former apprentice, Edmund Draper. By 1832 Stancliffe was again in business on his own, advertising that he manufactured "all kinds of mathematical, optical, and philosophical instruments," including surveyor's compasses, theodolites, sextants, and quadrants.

Ref: Robert C. Miller, "Benjamin Stancliffe and His Successors: A Century of Mathematical Instrument Makers in Philadelphia," Rittenhouse 11 (1996): 1-13.